im really wondering about this too. I know there has always been a few that do it but it is becoming such a problem these days that there has to be something else behind it. There is a theory that it's no-coders using software to send/receive CW and just call until they see their call sign decoded. I guess there could be something to that b/c thats how they do it on FT8/4 . . . for anyone with experience, it makes ZERO sense to keep sending your call if he's not calling you. Perhaps it's more difficult to start / stop whatever CW software they're using..